Prevalence and factors associated with diabetes-related distress in type 2 diabetes patients: a study in Hong Kong primary care setting.

Diabetes-related distress (DRD) refers to the psychological distress specific to living with diabetes. DRD can lead to negative clinical consequences such as poor self-management. By knowing the local prevalence and severity of DRD, primary care teams can improve the DRD evaluation in our daily practice. This was a cross-sectional study conducted in 3 General Out-patient Clinics (GOPCs) from 1 December 2021 to 31 May 2022. A random sample of adult Chinese subjects with T2DM, who regularly followed up in the selected clinic in the past 12 months, were included. DRD was measured by the validated 15-item Chinese version of the Diabetes Distress Scale (CDDS-15). An overall mean score ≥ 2.0 was considered clinically significant. The association of DRD with selected clinical and personal factors was investigated. The study recruited 362 subjects (mean age 64.2 years old, S.D. 9.5) with a variable duration of living with T2DM (median duration 7.0 years, IQR 10.0). The response rate was 90.6%. The median HbA1c was 6.9% (IQR 0.9). More than half (59.4%) of the subjects reported a clinically significant DRD. Younger subjects were more likely to have DRD (odds ratio of 0.965, 95% CI 0.937-0.994, p = 0.017). Patients with T2DM in GOPCs commonly experience clinically significant DRD, particularly in the younger age group. The primary care clinicians could consider integrating the evaluation of DRD as a part of comprehensive diabetes care.

SAP102 regulates synaptic AMPAR function through a CNIH-2-dependent mechanism.

The postsynaptic density (PSD)-95-like, disk-large (DLG) membrane-associated guanylate kinase (PSD/DLG-MAGUK) family of proteins scaffold α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) complexes to the postsynaptic compartment and are postulated to orchestrate activity-dependent modulation of synaptic AMPAR functions. SAP102 is a key member of this family, present from early development, before PSD-95 and PSD-93, and throughout life. Here we investigate the role of SAP102 in synaptic transmission using a cell-restricted molecular replacement strategy, where SAP102 is expressed against the background of acute knockdown of endogenous PSD-95. We show that SAP102 rescues the decrease of AMPAR-mediated evoked excitatory postsynaptic currents (AMPAR eEPSCs) and AMPAR miniature EPSC (AMPAR mEPSC) frequency caused by acute knockdown of PSD-95. Further analysis of the mini events revealed that PSD-95-to-SAP102 replacement but not direct manipulation of PSD-95 increases the AMPAR mEPSC decay time. SAP102-mediated rescue of AMPAR eEPSCs requires AMPAR auxiliary subunit cornichon-2, whereas cornichon-2 knockdown did not affect PSD-95-mediated regulation of AMPAR eEPSC. Combining these observations, our data elucidate that PSD-95 and SAP102 differentially influence basic synaptic properties and synaptic current kinetics potentially via different AMPAR auxiliary subunits. NEW & NOTEWORTHY Synaptic scaffold proteins postsynaptic density (PSD)-95-like, disk-large (DLG) membrane-associated guanylate kinase (PSD-MAGUKs) regulate synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) function. However, the functional diversity among different PSD-MAGUKs remains to be categorized. We show that distinct from PSD-95, SAP102 increase the AMPAR synaptic current decay time, and the effect of SAP102 on synaptic AMPAR function requires the AMPAR auxiliary subunit cornichon-2. Our data suggest that PSD-MAGUKs target and modulate different AMPAR complexes to exert specific experience-dependent modification of the excitatory circuit.

Progressive maturation of silent synapses governs the duration of a critical period.

During critical periods, all cortical neural circuits are refined to optimize their functional properties. The prevailing notion is that the balance between excitation and inhibition determines the onset and closure of critical periods. In contrast, we show that maturation of silent glutamatergic synapses onto principal neurons was sufficient to govern the duration of the critical period for ocular dominance plasticity in the visual cortex of mice. Specifically, postsynaptic density protein-95 (PSD-95) was absolutely required for experience-dependent maturation of silent synapses, and its absence before the onset of critical periods resulted in lifelong juvenile ocular dominance plasticity. Loss of PSD-95 in the visual cortex after the closure of the critical period reinstated silent synapses, resulting in reopening of juvenile-like ocular dominance plasticity. Additionally, silent synapse-based ocular dominance plasticity was largely independent of the inhibitory tone, whose developmental maturation was independent of PSD-95. Moreover, glutamatergic synaptic transmission onto parvalbumin-positive interneurons was unaltered in PSD-95 KO mice. These findings reveal not only that PSD-95-dependent silent synapse maturation in visual cortical principal neurons terminates the critical period for ocular dominance plasticity but also indicate that, in general, once silent synapses are consolidated in any neural circuit, initial experience-dependent functional optimization and critical periods end.